A 4th-Generation (4G) system is designed on the basis of a linear receiver and orthogonal transmission. The linear receiver may be implemented conveniently while ensuring the system performance, and the orthogonal transmission may be used to simplify the implementation of a receiving end. FIG. 1 is a schematic view showing data transmission on the basis of an orthogonal design, where a plurality of different pieces of data is transmitted on orthogonal physical resources respectively, and each piece of data is transmitted on a corresponding one physical resource. All the pieces of data are orthogonal to each other, so no interference occurs among them.
Due to the limited radio resources, it is impossible for the orthogonal system to provide system capacity for multi-user transmission. The data transmission on the basis of the orthogonal design has a defect of small system capacity, i.e., the data transmission capability for the system is relatively low.
Currently, NTT DoCoMo has proposed in WO2012161080 a non-orthogonal multi-address access approach on the basis of energy distribution, which may provide performance gains as compared with the orthogonal system. However, due to restriction on the degree of freedom for the energy distribution, its system capacity is still insufficient, and the data transmission capability is still low.